The field of microfluidics has matured significantly over the past two decades. Compelling platforms have been produced to address problems in traditional cell biology techniques that were previously too difficult to solve. Limitations of traditional cell biology techniques have been primarily due to onerous labor requirements and limited spatial and temporal control of the cells' microenvironment. Microfluidics has provided significant efficiency gains by reducing reagent and cell requirements that, in turn, has allowed for high-throughput processing and analysis of a large array of experimental conditions. Microfluidic systems also offer significantly greater control of the cells' microenviroment, such as flow rate, extracellular matrix (ECM) properties, and soluble factor signaling (e.g., forming a chemical gradient in diffusion dominant conditions). However, for microfluidics to make further inroads into cell biology, new microfluidic assays must be cheaper, faster, and in qualitative agreement with techniques traditionally used by biologists. It can be appreciated that microfluidics has tremendous potential to contribute to the development of drug therapies to fight cancer, point-of-care diagnostics for HIV in developing countries, and numerous other applications that are critical to the health and well being of individuals worldwide.
While current microfluidic devices provide a significant improvement in the ability to study fundamental aspects of cell biology, the adoption of microfluidic devices in clinical settings has been slow due to the high level of technicality and external equipment required. For example, current microfluidic assay methods require steps such as washing, flushing, pipetting, and transferring of cells and other materials. As such, most conventional microfluidic devices typically incorporate external elements, such as tubing and syringe pumps, to provide the valving and the mixing functionality necessary to enable an entire assay to be performed within a microfluidic system. These external elements diminish the simplicity and advantages of a microfluidic platform for biological assays. Hence, it is highly desirable to provide a handheld, disposable microfluidic device capable of performing assays which does not require any external equipment to operate and which can be adapted to a wide range of situations.
Therefore, it is a primary object and feature of the present invention to provide a microfluidic device and a method for performing handheld diagnostics and assays which do not require any external equipment to operate and which can be adapted to a wide range of situations.
It is a further object and feature of the present invention to provide a microfluidic device and a method for performing diagnostics and assays, which are handheld and disposable.
It is a still further object and feature of the present invention to provide a microfluidic device and a method for performing handheld diagnostics and assays which are simple to use and inexpensive to manufacture.
In accordance with the present invention, a microfluidic device is provided for handheld diagnostics and assays. The microfluidic device includes a base having outer surface and a channel therethough for receiving fluid therein. The channel has input and output ports communicating with the outer surface. The microfluidic device also includes a lid having an outer surface, a first well having a port communicating with the outer surface of the lid, and a second well having a port communicating with the outer surface. The lid is moveable between a first disengaged position and a second engaged position wherein the first port of the lid is adjacent the input port of the channel and the second port is adjacent the output port of the channel.
A membrane may extend over the input port of the lid and a piercing element may be operatively connected to the lid. The piercing element is moveable between a first retracted position and a second extended position wherein the piercing element pieces the membrane. The piercing element may include a plunger receivable in the lid and a needle extending from the plunger. The plunger is moveable between a first retracted position and a second extended position wherein the needle pierces the membrane. The needle has a terminal end and is moveable from a first retracted position wherein the terminal end of the needle is received in the first well in the lid and a second extended position wherein the terminal end of the needle projects from the lid in response to the movement of the plunger from the first retracted position and the second extended position.
A fluid absorbent may be received in the second well of the lid to communicate with fluid in the channel of the base with the lid in the engaged position. It is further contemplated for a substance source to be receivable in the first well of the lid. The substance source includes substance for diffusing into fluid in the channel of the base with the lid in the engaged position. The substance source may include a porous media to house the substance.
In accordance with a further aspect of the present invention, a microfluidic device is provided for handheld diagnostics and assays. The microfluidic device includes a base having outer surface and a channel therethough for receiving fluid therein. The channel has input and output ports communicating with the outer surface. A lid has an outer surface and is connectable to base. The lid includes a first well having an interior and a port communicating with the outer surface of the lid and a second well having a port communicating with the outer surface. A membrane extends over the port of the first well for isolating the interior thereof. The lid is moveable between a first disconnected position and a second connected position wherein the first port of the lid is adjacent the input port of the channel and the second port is adjacent the output port of the channel.
The membrane may be removable or, alternatively, a piercing element may be operatively connected to the lid. The piercing element is moveable between a first retracted position and a second extended position wherein the piercing element pieces the membrane. The piercing element may include a plunger receivable in the lid and a needle extending from the plunger. The plunger is moveable between a first retracted position and a second extended position wherein the needle pierces the membrane. The needle has a terminal end and is moveable from a first retracted wherein the terminal end of the needle is received in the first well in the lid and a second extended position wherein the terminal end of the needle projects from the lid in response to the movement of the plunger from the first retracted position and the second extended position.
A fluid absorbent may be receivable in the second well of the lid so as to communicate with fluid in the channel of the base with the lid in the connected position. In addition, it is contemplated to provide a substance source in the first well of the lid. The substance source includes substance for diffusing into fluid in the channel of the base with the lid in the connected position. The substance source may include a porous media to house the substance.
In accordance with a still further aspect of the present invention, a method is provided for handheld diagnostics and assays. The method includes the steps of providing a channel having an input and an output and positioning a lid having first and second wells adjacent the channel. The first well has a predetermined substance therein. Thereafter, the first well is allowed to communicate with the input of the channel.
A membrane may be provided over the first well. The step of allowing the first well to communicate with the input of the channel may include the additional step of piercing the membrane. It is contemplated to draw the predetermined substance into the channel, e.g., by bringing an absorbent into contact with the output of the channel. The predetermined substance may include particles for diffusing into fluid in the channel and a porous media to house the particles.